An Evidenced-Based Review of the Prevention of Venous Thromboembolism in Traumatic Patients with Intermittent Pneumatic Compression Devices

Objective To search, evaluate, and summarize the best evidence of intermittent pneumatic compression devices to prevent venous thromboembolism in trauma patients. Method Evidence retrieval was conducted from top to bottom according to the “6S” evidence model, including guidelines, clinical decision making, evidence summary, expert consensus, and systematic reviews. The retrieval time limit was from the establishment of the database to August 31, 2022. Two researchers independently evaluated the quality of the literature, extracted evidence, and summarized evidence. Results A total of 140 studies were obtained in the literature retrieval, and 50 studies were obtained after rechecking and reading the title and abstract. After combining the inclusion and exclusion criteria, 19 studies were finally included. Among them, there were 12 guidelines, 1 clinical decision making, 1 evidence summary, 1 expert consensus, and 4 systematic reviews. The 27 best pieces of evidence were summarized from the four dimensions of pretreatment evaluation, contraindications and applicable conditions, treatment strategies, training, and patient education. Conclusion This study summarized the evidence of using an intermittent pneumatic compression device to prevent venous thromboembolism in trauma patients and provided the basis for scientific and effective standardized management of mechanical thromboembolism prevention. When applying evidence, it is necessary to combine clinical practice and patient wishes and select evidence pertinent to improving the effectiveness of intermittent pneumatic compression devices in preventing venous thromboembolism. In addition, compliance with the clinical application of IPC is relatively low, so we should start from two aspects before the application of evidence. We should not only increase the number of IPCs but also strengthen the training of VTE prevention knowledge and practical skills of medical staff to provide good health education for patients and their families to improve compliance with the clinical application of IPC.


Introduction
Trauma has become one of the main problems afecting health [1], and its mortality rate ranks third in the disease mortality spectrum [2]. Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE) [3], is a common complication in trauma patients [4] and the main cause of death in hospitalized trauma patients [5]. Te risk of hospital-related VTE after multiple traumas is high, at more than 50% [6,7]. Terefore, as a high-risk group for VTE, it is necessary for trauma patients to carry out early and active thrombosis prevention [5,8]. Mechanical thromboprophylaxis is widely used in trauma patients because of its good practicability, simple operation, few complications, and low bleeding risk [4,5]. When there are contraindications to using drugs to prevent VTE, patients with trauma will implement mechanical thrombosis prevention [9]. Te guide also recommends intermittent pneumatic compression devices (IPCs) for the prevention of VTE in trauma patients [10,11]. IPC is a kind of circulatory infation through a compression device to simulate the contraction and relaxation of muscle movement to strengthen the blood fow of the deep vein and prevent thrombus [9,12]. At present, IPC mechanical prevention is often used as a supplement to drug prevention. Although many guidelines on the treatment and management of VTE have been issued internationally, many hospitals have formulated various strategies to prevent VTE, but the formulation of preventive measures lacks a certain evidencebased basis. Tis study uses evidence-based research methods to comprehensively summarize the best evidence of using IPC to prevent VTE in trauma patients, aiming to provide operable reference standards for the implementation of scientifc and efective mechanical thrombosis prevention.

Clarifying Research Issues.
We used the PIPOST model developed by JBI as a tool to construct evidence-based questions [13], that is, the target population of evidence application P (population): trauma patients, age ≥18 years old; Intervention I: IPC; P (professional): hospital managers and medical staf; Outcome index O (outcome): DVT incidence, pulmonary embolism incidence, VTE incidence; Evidence application site S (setting): hospital (surgery, trauma services, ICU); Type of evidence T (type of evidence): guidelines, systematic reviews, evidence summary, clinical decision making, expert consensus/opinion/position statement, and original research closely related to evidence.

Literature Retrieval Strategy.
We used "trauma * " OR "polytrauma" OR "wound * " OR "injury * " OR "multiple injury") AND ("intermittent pneumatic compression devices * " OR "intermittent pneumatic compression * " OR "pneumatic compression * " OR "sequential compression devices * " OR "pneumatic compression hose" OR "mechanical thromboprophylaxis") AND ("venous thromboembolism * " OR "deep vein thrombosis * " OR "Tromboembolism * " OR "thromboprophylaxis * " as the search keywords. According to the "6S" evidence model, we searched BMJ Best Practice (1), UpToDate (4), Joanna Briggs Institute Evidence-Based Health Care Center Database (JBI) (1), National Guidelines Clearinghouse (NGC) (1), National Institute for Health and Care Excellence (NICE) Registered Nurses' Association of Ontario (RNAO) (0), Scottish Intercollegiate Guidelines Network (SIGN) (1), Guidelines International Network (GIN) (1), EBSCO (0), Cochrane Library (1), PubMed (9), Embase (0), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (0), American College of Chest Physicians (ACCP) (0), and European Society for Vascular Surgery (ESVS) (0). Te retrieval time was from the establishment of the database to August 31, 2022. Literature inclusion criteria were as follows: the subjects were trauma inpatients aged ≥18 years old; the content of the literature involved the evaluation, intervention, or management of VTE prevention by using intermittent air pressure therapy devices in trauma patients; and evidence types included guidelines, clinical decision making, evidence summary, expert consensus, systematic reviews, and original research related to evidence. Exclusion criteria were as follows: (1) documents with duplicate publications, incomplete information, and inability to obtain full text; (2) document types mainly include plans, drafts, reports, and abstracts; and (3) research that did not pass document quality evaluation.

Literature Quality
Evaluation. Te quality evaluation of the guidelines adopts the 2012 version of the Appraisal of Guidelines for Research and Evaluation (AGREE II) [14]. Te scale covers a total of 23 items in 6 felds and 2 additional overall evaluation items. Each item is evaluated from 1 point (strongly disagree) to 7 points (strongly agree). Te score of each feld is equal to the total score of the items included in the feld and is standardized as the percentage of the highest possible score in the feld. Te additional 2 overall evaluation items are scored from 1 to 7 points (1 � lowest quality; 7 � highest quality). Te AMSTER (Assessment of Multiple Systematic Reviews) scale is used for systematic reviews [15]. Te scale includes 11 items, and the item evaluation options can be "Yes, No, unclear, and not used." Te quality evaluation standard of expert consensus adopts the expert consensus evaluation standard of Australia's JBI Evidence-Based Health Care Center [16] to evaluate such research. Te evaluation tool includes 7 items, and each item is judged by "Yes, No, unclear, and inapplicable." Evidence summary and clinical decision making are based on the original evidence level and recommendation level.

Evidence Classifcation and Recommendation Level.
An evidence-based group consisting of 10 experts in the feld of critical care medicine and traumatology was established, including 2 evidence-based experts, 2 doctors in the department of critical care medicine, 2 doctors in the trauma services, 2 vascular surgeons, 1 nurse in the department of critical care medicine, and 1 nurse in the trauma services. Te level and recommendation level of evidence are determined by the JBI evidence preclassifcation and evidence recommendation level system (2014 version) [17]. According to diferent types of evidence, the system divides them into Levels 1∼5 (Level 1 is the highest level, and Level 5 is the lowest level). Te level of evidence is related to the rigor of the research design. At the same time, the recommendation strength of the selected evidence is determined according to its FAME attributes (validity, feasibility, suitability, and clinical signifcance), which are level A recommendation (strong recommendation) and level B recommendation (weak recommendation) (Figures 1 and 2).

Literature Quality Evaluation
Process. Two researchers who have received evidence-based medicine training will conduct independent evaluations according to the corresponding standards of diferent document types. If the evaluation results cannot be agreed upon, the third evidencebased medicine expert can discuss until reaching a consensus. When the conclusions of evidence from diferent sources are in confict, the inclusion principle followed in 2 Emergency Medicine International this paper is evidence-based evidence frst, high-quality evidence frst, and the latest published literature frst.

Literature Retrieval Results.
A total of 140 studies were obtained in the literature retrieval, and 50 studies were obtained after rechecking and reading the title and abstract. After combining the inclusion and exclusion criteria, 19 studies were fnally included. Among them, there were 12 guidelines, 1 clinical decision making, 1 evidence summary, 1 expert consensus, and 4 systematic reviews (see Table 1 for the general characteristics of the included studies).

Quality Evaluation of the Guide.
In this study, the correlation coefcients within diferent groups was used to test the consistency of the quality evaluation of the guidelines. A total of 12 guidelines [6,10,11,[18][19][20][21][22][23][24][25][26] were included in this study. Te ICC values were >0.8, and the consistency of the evaluation was good. Table 2 shows the standardized percentage and comprehensive evaluation results of each feld of the guide.

Quality Evaluation of Clinical Decision Making and
Evidence Summary. Tis study included 1 clinical decision from UpToDate [5] and 1 summary of evidence from JBI [27]. A total of 6 studies were cited, all of which were based on the existing evidence level and recommendation level of the original text.

Quality Evaluation of Expert Consensus.
Tis study included one expert consensus. Te reference [28]is from the United States Trauma Surgery Intensive Care Board. In this expert consensus, according to item 6, 'Is there any inconsistency between the proposed points and previous research', is evaluated as 'No', and the other fve items are evaluated as 'Yes'. Te overall quality of this expert consensus is high.

Quality Evaluation of Systematic Reviews.
Tis study included four systematic reviews [29][30][31][32], one from the Cochrane Library and three from PubMed. Among them, the evaluation results of 11 items in the study of Lozano et al. [29] are "yes," with high overall quality, and are allowed to be included. In O'Connell et al.'s study, according to the fourth item "has the publication been included in the inclusion A-level recommendation: Strong recommendation B-level recommendation: Weak recommendation 1. Clearly show that the intervention does more good than harm or does more harm than good 2. High-quality evidence supports the application 3. Favorable or no impact on resource allocation 4. The patient's values, wishes, and experiences are taken into account 1. The evidence is unclear that the benefits of interventions outweigh the harms or the harms outweigh the benefits 2. There is evidence to support the application, but the quality of the evidence is not high enough 3. Beneficial but small or no impact on resource allocation 4. Partly taking into account the patient's values, wishes, and experiences Emergency Medicine International   Emergency Medicine International criteria", its evaluation result was "no", while the evaluation results of other items were "yes". Overall, this study has a complete design, high overall quality, and can be used as an included literature.

Summary of Evidence.
Tis study systematically evaluated and analyzed 19 studies, comprehensively sorted out the evidence, and fnally formed four dimensions of pretreatment evaluation, taboos and applicable conditions, treatment strategies, training, and patient education, with 27 best pieces of evidence (Table 3).

Pretreatment Evaluation.
Trauma patients are high-risk patients with VTE. All hospitalized trauma patients should undergo VTE risk assessment and bleeding risk assessment, which is helpful to further grade the risk of thrombosis to give corresponding thromboprophylactic measures [18]. At present, the Wells scale, which is widely used in clinical practice, is developed based on outpatient patients, so it is not applicable to inpatients with trauma [33]. Te Padua scoring scale is applied to nonsurgical patients. At the same time, the Risk Assessment Profle for Tromboembolism (RAPT) can also be used for the risk assessment of VTE in trauma patients [34]. At present, the bleeding risk assessment models of VTE patients include the International Medical Prevention Registry on Venous Tromboembolism (IMPROVE), Kuijer score, and the European Multicenter Tromboembolism Registry (Registro Informatizado de la Enfermedad Trombo-Embolica, RIETE) [35], among which the bleeding risk assessment model for VTE prevention only has the IMPROVE score, which is applicable to nonsurgical patients. Te prediction ability of bleeding risk for surgical patients in VTE high-risk groups needs to be verifed; however, other bleeding risk assessment models still lack validation and comparison of clinical use [36,37]. Te guidelines do not recommend any scoring model but list the risk factors related to bleeding [10,35]. Medical staf can choose appropriate preventive measures according to the type of trauma, risk factors for VTE, and bleeding risk. Te third piece of evidence describes the diagnostic evaluation of the diagnosis of VTE. DVT and pulmonary embolism are contraindications of IPC treatment and should be identifed early in the prevention process. When DVT or pulmonary embolism is suspected, laboratory examination and imaging examination are required to make a defnite diagnosis regardless of whether the clinical manifestation is typical.

Contraindications and Applicable
Conditions. At present, routine VTE prevention methods include basic prevention, drug prevention, and mechanical prevention. Te multimodal approach combining IPC and drug prevention is the most efective in reducing venous thromboembolism [38]. For patients with a moderate to high risk of VTE, if there is no contraindication for drug prevention, drug prevention is the frst choice for VTE prevention, and drug prevention combined with mechanical prevention has a lower incidence rate of VTE than drug prevention alone. If there are contraindications, mechanical prevention can be an important choice. For low-risk patients, mechanical prevention can also efectively reduce the incidence rate of VTE [39]. Domestic and foreign guidelines recommend IPC as the frst choice for mechanical prevention [25][26][27]30]. Contraindications should be routinely screened before IPC treatment.

Treatment Strategy
(1) At present, the efectiveness of IPC in preventing VTE has been recognized, but its compliance in clinical application is not high. Based on an observational study, the overall compliance with IPC treatment is only 29% [40,41]. Te possible reasons are that the patient or his family members do not know the purpose of use, the patient is intolerant or uncomfortable during use, and the use site may have adverse reactions (such as lower limb circulation disorder, skin allergy, or stress injury). Terefore, prior to IPC treatment, informed consent of the patient or family member should be obtained to explain the purpose of IPC treatment, precautions during treatment, and observation of adverse reactions. At the same time, limb evaluation and IPC device evaluation should be carried out to strengthen the key evaluation of the efectiveness of wearing the device, the patient's tolerance, comfort, and the skin of the use site. At present, there are various intermittent air pressure devices [31], but the guide does not make recommendations for specifc IPC equipment [25]. In addition, there is no signifcant diference in the treatment efect between diferent infating methods, and there is no signifcant difference in the treatment efect between diferent lengths of cuf [31]. When used, the appropriate IPC can be selected according to the wishes of the patient and the conditions of the hospital. (2) Traumatic patients have a tendency of thrombosis within 24 hours after injury, and their blood is also in a hypercoagulable state. Generally, this tendency is most obvious approximately 5 days after injury, and it begins to decline 14 days after injury. Terefore, if there is no contraindication, preventive measures should be started as soon as possible [42]. Generally, mechanical prevention is relatively safe. On the premise that the patient can tolerate it, the use time should be extended as much as possible, but the dynamic observation and evaluation of the patient and device in the treatment cannot be ignored. Medical staf should conduct dynamic observation and evaluation of patients and equipment during IPC treatment of patients. Once the possibility of new DVT or pulmonary embolism is suspected, the treatment should be stopped immediately, and the 6 Emergency Medicine International  (2) For patients with high risk of bleeding (craniotomy, traumatic brain injury, spinal cord injury repair, major trauma, coagulation dysfunction, etc.) or patients with contraindications for drug thrombosis prevention (such as active hemorrhage and intracranial hemorrhage) or patients with hemodynamic instability caused by these conditions, drug prevention should be stopped and IPC mechanical prevention should be used.

Training and Patient Education.
In clinical practice, low compliance with IPC treatment is related not only to the above patient factors but also to medical staf factors. A lack of VTE-related training for medical staf will directly afect the efect of IPC mechanical prevention [44], and strengthening the training of medical staf is a technical guarantee to promote the implementation of VTE prevention measures. A current survey study shows that strengthening the training of medical staf can improve compliance with IPC treatment from 26% to 44% [38]. In addition, the information needs of patients are considered an important factor afecting compliance [38]. It is also important to carry out health education for patients or family members (long-term caregivers) receiving IPC treatment. Te medical staf of the VTE high-risk department should communicate in a timely manner with the patients or their families (long-term caregivers), strengthen the popular science education of VTE prevention knowledge, and promote the implementation of VTE prevention measures.

Conclusion
VTE is one of the more common and preventable complications of trauma patients during hospitalization. As a strategy for thrombosis prevention, IPC is an important choice. Tis study uses scientifc research methods to summarize the 27 best studies for IPC to prevent VTE in trauma patients, providing an evidence-based basis for the implementation of clinical IPC. We also want to see the update of IPC equipment. Wall et al. [45] used a new portable mechanical device (Wearable Intermittent Compression, WIC) for intermittent and continuous compression of leg grading to replace the traditional IPC mechanical system, making the compression device work in a mode similar to IPC but with shorter and faster cycle. Te study showed that the new device signifcantly increased the venous fow compared with the baseline treatment of ECS and the traditional IPC treatment. In addition, WIC solves the additional limitations of IPC treatment by providing more fexible material selection, including breathable fabrics and less overall contact surface area. Mosti and Partsch [46] designed a new portable battery-driven compression device, which can automatically adjust the pressure to adapt to the change of body position and connect to the wrapped leg sets with diferent material hardness. In order to standardize the assessment, prevention, and treatment of VTE in trauma patients, we will record the leg ejection fraction (EF) and apply compression pressure under diferent pressure materials when lying, standing, and walking. In addition, in the process of promoting the implementation of evidence, it is also necessary to note that this study only includes the published literature. It is recommended that medical personnel should fully and comprehensively evaluate the clinical situation in the process of clinical application of evidence and apply the best evidence in combination with the wishes of patients and the conditions of hospitals to improve the effectiveness of IPC in preventing thrombosis. Second, although there are few reports of adverse events related to IPC treatment, the safety of IPC application should also be considered by medical staf. In the selection of IPC, medical staf should select the appropriate IPC according to the actual situation of patients to ensure its safety. In addition, compliance with the clinical application of IPC is relatively low, so we should start from two aspects before the application of evidence. We should not only increase the number of IPCs but also strengthen the training of VTE prevention knowledge and practical skills of medical staf to provide good health education for patients and their families to improve compliance with the clinical application of IPC.